Wound treatment apparatus

ABSTRACT

A control unit is adapted for use with a vacuum wound bandage. The control unit has a canister to collect waste material from the vacuum wound bandage, a fluid source to irrigate the wound, and a door to at least partially cover the fluid source.

RELATED APPLICATION

This disclosure is a division of U.S. Ser. No. 10/159,720, filed May 31,2002, which is hereby incorporated herein by reference. U.S. Ser. No.10/159,720 is U.S. Pat. No. 6,824,533, issued Nov. 30, 2004. U.S. Ser.No. 10/159,720 is a continuation-in-part of U.S. application Ser. No.09/725,666, which was filed Nov. 29, 2000 and which is herebyincorporated by reference herein. U.S. Ser. No. 09/725,666 is U.S. Pat.No. 6,755,807, issued Jun. 29, 2004. U.S. Ser. No. 09/725,666 is aregular utility patent application claiming the benefit of the filingdate of U.S. Provisional Application Ser. No. 60/167,753, filed on Nov.29, 1999.

TECHNICAL FIELD

The present disclosure relates to wound treatment apparatus for use withvacuum bandages of the type that dispenses fluid to a wound and drawsfluid away from the wound.

BACKGROUND AND SUMMARY

Medical professionals, such as nurses and doctors, routinely treatpatients having surface wounds of varying size, shape, and severity. Itis known that controlling the topical atmosphere adjacent a wound canenhance the healing process. For example, by applying medicinal agentsor even water over a wound, dirt and bacteria are either killed orwashed away, thereby promoting healing. In addition, applying a negativepressure or vacuum to a wound draws out exudate, which might containdirt and bacteria, from the wound to further promote healing.

Conventional treatment of a surface wound involves placement of apacking or dressing material, such as cotton, gauze, or otherbandage-like material directly in contact with the patient's wound.Often there is a need to change the dressing material frequently becauseit becomes saturated with exudate discharged from the wound. Somedressings include an apparatus attached thereto for applying a vacuumthrough the bandage to the wound to draw exudate and promote healing.

According to the present disclosure, a control unit is adapted for usewith a vacuum wound bandage. The control unit comprises a control moduleto provide a negative pressure through the vacuum wound bandage and acanister having an interior region to collect waste material from thevacuum wound bandage and a latch to couple the canister to the controlmodule. The latch extends through the interior region. Illustratively,the latch is operable to move the canister into sealing engagement withthe control module. Further illustratively, the canister has a sleevepositioned within the interior region, and a portion of the latch ispositioned within the sleeve.

According to another aspect of the disclosure, the control unitcomprises a vacuum source to provide a desired negative pressure throughthe vacuum wound bandage to treat the wound, a pressure sensor, and acanister. The canister has a chamber to collect waste material from thevacuum bandage, an inlet port to introduce waste material from thevacuum bandage into the chamber, an outlet port to communicate with thechamber and the vacuum source, and a pressure port to communicate withthe chamber and the pressure sensor. The pressure port is positioned toallow the pressure sensor to sense the pressure within the chamber whenthe waste material within the chamber at least partially occludes theoutlet port so as to prohibit the vacuum source from providing thedesired negative pressure within the chamber.

According to another aspect of the disclosure, the control unitcomprises a fluid source to irrigate the wound, a housing carrying thevacuum source and the fluid source, and a door movable relative to thehousing between an opened position uncovering the fluid source and aclosed position at least partially covering the fluid source. Thecontrol unit further comprises a latch coupled to the door for movementrelative to the door between a latched position blocking movement of thedoor from its closed position to its opened position and a releaseposition allowing the door to move between its closed position and itsopened position. According to another aspect of the disclosure, the doorhas a mount supporting the fluid source.

Additional features and advantages of the apparatus will become apparentto those skilled in the art upon consideration of the following detaileddescriptions exemplifying the best mode of carrying out the apparatus aspresently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

The illustrative apparatus will be described hereinafter with referenceto the attached drawings, which are given as non-limiting examples only,in which:

FIG. 1 is a perspective view of a wound treatment apparatus coupled to abandage attached to a patient;

FIG. 2 is a block diagram of the wound treatment apparatus of FIG. 1;

FIG. 3 is a schematic diagram of the wound treatment apparatus of FIG.1;

FIG. 4 is a side cross-sectional view of the wound treatment apparatusalong the lines A-A of FIG. 1;

FIG. 5 is a schematic block diagram of the vacuum evacuating sub-systemof the wound treatment apparatus of FIG. 1;

FIG. 6 is a cross-sectional view of a waste disposal canister of thewound treatment apparatus along the lines B-B of FIG. 1;

FIG. 7 is a partially exploded perspective view of the wound treatmentapparatus of FIG. 1 with the waste canisters removed;

FIG. 8 is a perspective view of another embodiment of the woundtreatment apparatus;

FIG. 9 is a side diagrammatic view of the vacuum bandage and portions ofthe wound treatment apparatus of FIG. 1;

FIG. 10 is a perspective view of the wound treatment apparatus of FIG. 1with the waste canister removed;

FIG. 11 is a front elevational view of a waste canister;

FIG. 12 is a side elevational view of the waste canister of FIG. 11; and

FIG. 13 is a top view of the waste canister of FIG. 11.

FIG. 14 is a perspective view of another wound treatment apparatusshowing a pair of canisters arranged for insertion into respectivereceptacles formed in the sides of a housing of a control unit andshowing a fluid source arranged for insertion into a receptacle formedin the front of the housing;

FIG. 15 is an enlarged elevation view of a latch for a door of the woundtreatment apparatus of FIG. 14 showing the latch in a release position;

FIG. 16 is a view similar to FIG. 15 showing the latch in a latchedposition;

FIG. 17 is a fragmentary sectional view showing a syringe having aflange received by grooves of the door and the housing to retain abarrel of the syringe in place;

FIG. 18 is a perspective view of the rear of a control unit of the woundtreatment apparatus of FIG. 14 showing a carrying handle at the top ofthe control unit and a mounting bracket on a rear wall of the controlunit;

FIG. 19 is a perspective view of the rear of the control unit of FIG. 18with a rear wall removed;

FIG. 20 is an exploded perspective view of a waste collection canisterof the control unit;

FIG. 21 is a fragmentary perspective view of a portion of the canisterof FIG. 20 and a portion of a receptacle of the housing in which thecanister is received;

FIG. 22 is a side sectional view of the canister partially inserted intothe receptacle;

FIG. 23 is a side sectional view similar to FIG. 22 of the canisterinstalled within the receptacle;

FIG. 24 is an enlarged elevation view of the interface between the latchand a wall of the receptacle showing lugs of the latch aligned withlug-receiving spaces of an aperture formed in the receptacle wall;

FIG. 25 is an enlarged elevation view, similar to FIG. 24, showing thelugs of the latch misaligned with the lug-receiving spaces of theaperture to retain the canister in the receptacle;

FIG. 26 is a sectional view taken along line 26-26 of FIG. 25 showingengagement between the lugs and the receptacle wall;

FIG. 27 is a diagrammatic view of portions of the wound treatmentapparatus of FIG. 14;

FIG. 28 is a diagrammatic view of a three-chambered muffler.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplification set out hereinillustrates several embodiments of the apparatus, and suchexemplification is not to be construed as limiting the scope of thisdisclosure in any manner.

DETAILED DESCRIPTION OF THE DRAWINGS

An embodiment of wound treatment apparatus 2 is shown in FIG. 1. Woundtreatment apparatus 2 comprises a central unit housing 4, having woundtreatment systems 6, 8 appended to each side of housing 4. A userinterface 10 is shown positioned between each treatment system 6, 8.Central unit housing 4 is configured to be a portable unit allowing acaregiver to move housing 4 to wherever the patient is located and toclose proximity to the wound or wounds. Housing 4 is shown having ahandle portion 12 to assist the caregiver in moving housing 4. FIG. 1also shows wound treatment system 6 coupled to a bandage 14 attached toa patient's leg 16. Dispensing and evacuating tubes 18, 20 are coupledto both bandage 14 and system 6. Specifically, dispensing tube 18 iscoupled to a luer-lok port 22 extending from syringe 24. Syringe 24 isfilled with a fluid, typically saline, that empties through tube 18 andinto bandage 14, and ultimately onto a wound 300 positioned underbandage 14. (See also FIG. 9.) After contacting wound 300, the fluid andexudate from wound 300 are drawn from bandage 14 through evacuating tube20 and into a waste canister 26 where it is collected. It iscontemplated that the canister 26 can be discarded when filled andreplaced with a new canister 26.

Apparatus 2 comprises a second system 8 on the opposite side of housing4 from system 6. This configuration allows two wounds to be treatedsimultaneously with separate bandages, yet, under the control of asingle housing 4. Second bandage 15, as part of system 8, is coupled todispensing and evacuating tubes 28, 30, respectively, to perform thesame functions as described for system 6. (See FIG. 2.) User interface10 is provided to allow the caregiver to control either or both systems6, 8, to dispense fluid from either or both syringes 24, 224, and toevacuate from either or both bandages 14, 15. It is contemplated thateach wound treatment system 6, 8 will work independent of each other,thus, allowing the caregiver flexibility to apply an appropriate and,yet, possibly different level of treatment to each wound.

The arrangement of systems 6, 8 relative to user interface 10 on housing4 allows convenient interaction between systems 6, 8 and the caregiver.For example, syringes 24, 224 are conveniently positioned on oppositesides of user interface 10. Each syringe is partially covered by doors32, 33 on the front of housing 4. Each door 32, 33 swings outwardlyabout hinges 34, 36, allowing syringes 24, 224 to be removed andreplaced. Similarly, waste canisters 26, 27 are each positioned in acavity 9 provided on each side of housing 4. (See FIG. 7.) Each canister26, 27 includes a grip portion 40 for convenient removal andreplacement. Canisters 26, 27 are illustratively secured into eachcavity by a friction fit. (See FIG. 6.) It is appreciated, however, thatsyringes 24, 224 can be secured to other locations on housing 4.

The portability of apparatus 2 allows a caregiver to position it nearthe patient in preparation for treatment wherever the patient islocated. To prepare apparatus 2 for treatment, the caregiver securessyringes 24, 224, which contain fluid, to apparatus 2 in a mannerdescribed in greater detail below. The caregiver then couples tube 18 toport 22 and bandage 14, and tube 20 to bandage 14 and waste canister 26,for treatment of one wound. The caregiver then couples tube 28 to port222 and bandage 15, and tube 21 to bandage 15 and waste canister 27, fortreatment of a second wound. (See also FIG. 2.) The caregiver, throughthe use of user interface 10 can treat the patient by selectivelyirrigating the wounds with fluid and drawing exudate and the fluid fromthe wounds.

A diagram depicting how wound apparatus 2 operates is shown in FIG. 2. Acontroller 50 is provided in housing 4 and is an electronic control unitthat controls apparatus 2. Controller 50 receives user input from andprovides feedback to user interface 10 through lines 52, 54,respectively. It is contemplated that controller 50 will processinformation from both systems 6, 8, and provide appropriate andindependent input to each system. Controller 50 also monitors the statusof all various sensors, and provides input for the valves and motors, asdiscussed in further detail herein. Illustratively, user interface 10 iscomposed of a conventional graphic liquid crystal display (LCD) and amembrane switch panel.

A power supply 56 provides power to controller 50 and all the attendantsystems in housing 4. Power supply 56 can be a conventional externalwall socket supply (not shown), or be a battery pack supply (also notshown), or even be variations of both (e.g., a wall socket supply with abattery pack supply). Illustratively, power supply 56 is a medical gradepower supply providing an output of about 65-watts and a voltage ofabout 12VDC. It is contemplated that the power supply can be configuredfor 120V/60 Hz or 220-240V/50 Hz depending on whether housing 4 is usedin America or Europe. Illustratively, the battery power provides thedevice with power to operate for about 60 minutes without connection toan external power source. It is further contemplated that the batteriescan be rechargeable, and store energy when the device is connected to anexternal wall socket.

An attitude sensor 58 is provided in communication with controller 50through line 60. Attitude sensor 58 is, illustratively, a tilt switchwhich provides feedback to controller 50. If the switch is,illustratively, in the closed position, controller 50 will continue tooperate, but if the switch opens, controller will shut systems 6, 8down. For example, sensor 58 disables systems 6, 8 if housing 4 tilts ator greater than a predetermined amount, such as 45° from vertical in anydirection.

It is contemplated that controller 50, user interface 10, power supply56, and attitude sensor 58 are all common to and all operate with bothsystems 6, 8. Each system 6, 8 further comprises fluid dispensing andvacuum evacuating sub-systems 62, 64 and 66, 68. Fluid dispensingsub-system 62 comprises a syringe 24 having a plunger 70. (See also FIG.4.) Syringe 24 is, illustratively, a standard 60-ml medical syringeutilizing a luer-lok port 22. Plunger 70 is a conventional plunger thatextends into syringe 24 to dispense fluid through luer-lok port 22. Asyringe drive motor 72 is, illustratively, a 12VDC brushless electricmotor or stepper motor configured to provide rotational energy to asyringe drive 74. (See FIG. 4.) When a signal is sent from controller 50along line 76 to syringe drive motor 72, motor 22 applies torque andangular velocity to syringe drive 74 which is, illustratively, a powerscrew 322. (See also FIG. 4.) Power screw 322 translates rotationalmovement of the syringe drive motor 72 into translational movement. Thedrive has a guide 80 to limit a plunger interface 78 to motion along oneaxis. In the illustrated embodiment, syringe drive 72 provides about5.25 inches (13.3 cm) of travel of plunger interface 78, indicated byreference numeral 82, to evacuate the fluid contained in syringe 24.(See also FIG. 4.) Furthermore, syringe drive motor 72 and syringe drive74, as a system, provide about 27 pounds of linear force at a velocityof 1.45 inches (3.7 cm) per second to the plunger interface 78. Theresulting force created by the fluid exiting syringe 24 creates,illustratively, 4-PSIG to 6-PSIG positive pressure at wound 300.

A syringe home sensor 84 receives information from plunger interface 78,and provides feedback to controller 50 when syringe capture mechanism 88reaches its home position 79. A syringe full travel sensor 86 determineswhen syringe 24 is fully evacuated by sensing when plunger interface 78has reached fill travel. After sensor 86 has been activated, controller50 resets plunger interface 78 to home position 79 once syringe 24 isremoved.

Syringe capture mechanism 88 holds syringe 24 in place when thecaregiver places syringe 24 in apparatus 2. (See also FIG. 4.) Capturemechanism 88 is also configured to allow the caregiver to releasesyringe 24 from apparatus 2 when it is empty. Capture mechanism 88further includes a syringe sensor 90 that provides feedback tocontroller 50 through line 92 when syringe 24 is properly held incapture mechanism 88. Controller 50 prevents system 6 from operating ifsensor 90 does not detect syringe 50 being properly held in capturemechanism 88.

Connectors 94, 96 are provided at opposed ends of dispensing tube 18.Either one or both connectors 94, 96, when closed, block flow fromsyringe 24 to bandage 14. Such connectors 94, 96 allow the patient to bedisconnected from apparatus 2 without having to remove bandage 14 oreven shut apparatus 2 down.

A manual port 98 is also attached to dispensing tube 18 by an auxiliarytube 100. Port 98 permits the caregiver to attach a dispensing containerto the system to manually dispense fluid into bandage 14. It isappreciated, however, that port 98 is configured to be closed while nosyringe is attached to maintain a closed system.

The syringe and drive are illustrated as one approach for providing afluid source and a drive for irrigating a wound bed. It will beappreciated that containers other than syringes may be operated by adrive to expel irrigation fluid toward a wound surface. For example, anytype of container of fluid may be squeezed or reduced in volume by adrive mechanism to expel fluid. Also, as discussed in connection withFIG. 8, a container may be held at an elevated position to provide headpressure for irrigation fluid.

Connectors 104, 106, similar to connectors 94, 96, are provided atopposed ends of evacuating tube 20. Either one or both connectors 104,106, when closed, block flow from bandage 14 to waste canister 26. Suchconnectors 104, 106 also allow the patient to be disconnected fromapparatus 2 without having to remove bandage 14 or having to shut downapparatus 2.

Waste canister sensors 116, 118 are engaged when waste container 26 isproperly seated in apparatus 2. This prevents apparatus 2 from operatingwithout canister 26 seated properly in apparatus 2. As depicted in FIG.2, both sensors 116, 118 provide feedback to controller 50 through lines120, 122, confirming to the caregiver that canister 26 is seatedproperly in apparatus 2.

In the illustrated embodiment, waste canister 26 is a disposable unitthat “snaps into” side portion 38 of housing 4. (See also FIGS. 1 and6.) Illustratively, canister 26 includes a window (not shown) to allowmonitoring of the fluids. Illustratively, the fluid capacity of canister26 is about 500-ml.

The illustrated embodiment of waste canister 26 further includes ahydrophobic filter 108 that is in communication with both evacuatingtube 20 and vacuum pump 110. (See also FIG. 6.) Such filter 108 isconfigured to allow air, but not liquid, to pass. Accordingly, as fluidis drawn into canister 26, fluid is deposited into waste canister 26while the vacuum continues through filter 108 and pump 110.Illustratively, filter 108 is a 1.0-micron hydrophobic filter fixed intorear wall 407 of canister 26. (See FIG. 6.) Hydrophobic filter 108 alsoserves as a canister full mechanism 114 or valve that shuts off thevacuum supply to the canister 26 when the fluid level exceeds the “full”level 420. Because hydrophobic filter 108 prevents fluid from passing,once fluid covers filter 108, vacuum is prevented from passing as well.The absence of any vacuum in the system will cause the system to shutdown.

Vacuum pump 110 creates the negative pressure that is present throughcanister 26. For monitoring and controlling such negative pressure, thevacuum is present through several devices, including a vacuum pressuretransducer 124. Transducer 124 is coupled to line 128, extending fromcanister 26. (See FIG. 5.) Transducer 124 measures the negative pressurethat is present through canister 26. Transducer 124 then providesfeedback to controller 50 through line 128. Controller 50 monitors thenegative pressure by comparing the measured value from transducer 124with the caregiver-defined value entered into controller 50 through userinterface 10.

A proportional valve 130 is connected to line 126, through which thenegative pressure is present, and which comprises a flow orifice 132.(See also FIG. 5.) Flow orifice 132 selectively dilates or constricts,thereby controlling the negative pressure level through sub-system 66.Specifically, controller 50 provides a signal input to proportionalvalve 130 based on the level of the vacuum pressure determined fromfeedback of transducer 124 and comparing that level to thecaregiver-defined level. Orifice 132 then dilates or constricts, asnecessary, to produce the appropriate level of negative pressure.Illustratively, proportional valve 130 is fully constricted or closedwhen receiving no signal from controller 50, and dilates or opens toallow an illustrative maximum of two liters per minute at 250-mmHg(4.83-PSIG) vacuum when the proper signal from controller 50 is applied.

A vacuum regulator 134 is provided in line 126 between proportionalvalve 130 and pump. 110 as a mechanical limit control for pump 110.Regulator 134 mechanically establishes a maximum level of negativepressure that is present in the system. Thus, vacuum pump 110 will notphysically be able to draw a vacuum from bandage 14 beyond the maximumpressure. Illustratively, such maximum negative pressure or vacuum is250-mmHg (4.83-PSIG). In addition, when proportional valve 130, pursuantto a signal from controller 50, creates a negative pressure less thanthe maximum negative pressure level, a port 136, coupled to regulator134, opens so that pump 110 can draw more air to maintain a sufficientflow through pump 110, to prevent it from becoming damaged. A first airfilter 137 is illustratively associated with port 136, between port 136and pump 110, to filter particulates from the air prior to reaching pump110. illustratively, filter 137 is constructed of glass microfibers witha filtration rating of 25 microns. A second filter 139 is associatedwith pump 110 and an outlet 141. Filter 139 serves as an exhaust mufflerfor the air evacuated from pump 110.

Vacuum pump 110 is, illustratively, a diaphragm-type compressor thatflows about two liters per minute at 250-mmHg (4.83-PSIG) vacuum.Illustratively, vacuum pump 110 is mounted on the end of a single 12VDCbrushless motor 138 to drive the pump. It is appreciated, however, thatpump 110 can be of any other configuration, and mounted in any manner,so long as it draws a desired negative pressure through system 6. It isalso contemplated that a vacuum pump external to the housing 4 may be apart of the control system. For example, most medical facilities havevacuum ports near where patients are treated, each of which is served bya system vacuum (suction) pump. It is contemplated, therefore, that thepump 110 in the housing 4 may be an appropriate fitting which is, inturn, connected to a facility vacuum pump to provide a vacuum source tothe control system.

It is contemplated that port 136, filters 137, 139, electric motor 138,vacuum pump 110, and vacuum regulator 134 are all housed in a soundchamber 140. Illustratively, the interior of sound chamber 140 is linedwith a damping foil like the 3M Company's damping foil number 2552, forexample. Sound chamber 140 dampens vibration energy produced by thesecomponents, as well as assists in dissipating heat they generated.

As previously indicated, it is contemplated that controller 50, userinterface 10, power supply 56, and attitude sensor 58 are common to, andoperate with, both fluid dispensing and vacuum evacuating sub-systems62, 64 and 66, 68. Providing a second independently operable set ofsub-systems 64, 68 allows the caregiver to treat two wounds using asingle apparatus 2. Accordingly, second fluid dispensing and evacuatingsub-systems 64, 68 also shown in FIG. 2, comprise identical componentsas discussed regarding sub-systems 62, 66 and are labeled in acorresponding manner. For example, syringe motor drive 72 in sub-system62 is identified as syringe motor drive 172 in sub-system 64, and avacuum pump 110 in sub-system 66 is identified as vacuum pump 210 insub-system 68.

A schematic diagram of a portion of wound treatment apparatus 2 is shownin FIG. 3. Each system 6 and 8 is configured to operate in the samemanner. Specifically, FIG. 3 depicts the operation of system 6. Movementof plunger 70 into syringe 24 causes fluid stored in syringe 24 to exitinto tube 18 and into bandage 314 where it drains through orifices 302onto wound 300. Vacuum 110 applies a negative pressure through wastecanister 26 and bandage 314. Fluid and exudate are then drawn from wound300 out through tube 20 and into canister 26. The hydrophobic filter108, discussed in connection with FIG. 2, allows the vacuum to passthrough waste canister 26, yet, prevents any of the fluid from escaping,and depositing the fluid into pump 110.

The mechanism for moving plunger 70 into syringe 24, part of fluiddispensing sub-system 62, is shown in cross-sectional form in FIG. 4.The illustrated embodiment includes sub-system 62 positioned withinhousing 4. Specifically, a bracket frame 310 serves as the skeletalstructure for sub-system 62. Bracket 310 includes a base portion 312with an upwardly extending structural member 314 appending from one endthereof. A support portion 316 extends outwardly from member 314, and issuperposed above base portion 312. Extending from support portion 316 issyringe bracket 318. Syringe capture mechanism 88 is formed in bracket318, and is configured to receive syringe 24, as previously discussed.Bracket 318 and capture mechanism 88 are configured to suspend syringe24 with luer-lok port 22 directed upwardly. It is contemplated thatcapture mechanism 88 secures syringe 24 to bracket 318 by other means,including being friction-fitted, or secured with clips or bolts. To moveplunger 70, syringe drive 74 and plunger interface 78 are coupled toframe 310. Plunger interface 78 captures plunger 70 and provides upwardlinear motion to evacuate syringe 24. Interface 78 provides a releasemechanism for plunger 70 to remove syringe 24 at any position in thestroke.

Syringe drive 74 comprises syringe drive motor 72 and power screw 322.Power screw 322 is disposed through an aperture 324 in support portion316, and is rotatably coupled to motor 72. It is appreciated that motor72 can be a stepper or electric motor, for example. The lower end 326 ofpower screw 322 is positioned within a bearing cavity 328 within whichpower screw 322 rotates. Spaced in parallel to power screw 322 is guide80. Guide 80 is received in an aperture 330, also disposed in supportportion 316 at its upper end 332, and is received in cavity 334 at itslower end 336. Plunger interface 78 is configured to receive cap 338 ofplunger 70, and is coupled to a dual coupler 340. Dual coupler 340comprises two blocks 342, 344, each having bores 346, 348 disposed,respectively, there through. In the illustrated embodiment, bore 346 hasa smooth surface and is configured to receive guide 80. In contrast,bore 348 has a threaded surface and is configured to cooperate withthreads on power screw 322. Coupler 340 is movable upwardly anddownwardly in directions 350, 352. A hatched outline version of coupling340, indicated by reference numeral 354, is shown depicting plungerinterface 78 and plunger 70 moving upwardly in direction 350. As shownin FIG. 4, as plunger 70 is moved upwardly, head 356 is also movedupwardly, reducing the available space in syringe 24, thus, displacingany fluid in syringe 24 out of luer-lock port 22, thereby dispensing thefluid into tube 18 and into bandage 14. The movement of cap 356 isdepicted by the position of cap 356 in hatched lines moved to an upperposition indicated by reference numeral 358.

A cross-sectional view of waste canister 26 located in cavity 9 on side38 of housing 4 is shown in FIG. 6. Tube 20 is connected to acheck-valve assembly 400 coupled to recess 402 disposed in the frontwall 405 of canister 26. Check valve 400 is configured to allow fluidand exudate from bandage 14 to enter canister 26 and deposit in holdingspace 404 within canister 26, yet prevent any fluid already in space 404from exiting through valve 400. Check valve 400, thus prevents fluidfrom escaping when tube 20 is disengaged from valve 400. In addition,canister 26 can be discarded without any fluid escaping. Hydrophobicfilter 108 is located on the rear wall 407 of canister 26. A liquidsolidifier 29 is provided in space 404 to decease the fluidity of theexudate. This is a safety measure to lessen the chance of splashing orrun-off if canister 26 (or 27) is opened or broken.

Filter 108 in canister 26 is shown having an inlet 410 provided in space404 and an outlet 412 coupled to a connector 416 with a barrier ofhydrophobic material 414 provided there between. As previouslydiscussed, the hydrophobic material allows the vacuum to pass throughinlet 410 and outlet 412, yet prevents any fluid from passing. Similarto check valve 400, hydrophobic filter 108 too prevents any fluid fromescaping even when canister 26 is removed from housing 4. Outlet 412 offilter 108 is in communication with connector 416. Connector 416 isconfigured to receive and seal outlet 412 when canister is positioned incavity 9. Connector 416 is in communication with line 126 and ultimatelywith pump 110.

In the illustrated embodiment, hydrophobic filter 108 serves as both thecanister full mechanism 114 that shuts off the vacuum supply to thecanister 26 when the fluid level exceeds the “full” level as indicatedby reference numeral 420. When the fluid level is below inlet 410, asindicated by reference numeral 422, fluid continues to enter space 404through valve 400. When the fluid level 420 is above inlet 410, thefluid is acting as an air block. Fluid cannot pass through filter 108,but because the fluid level is above inlet 410, air cannot pass througheither. This causes a dramatic pressure drop (vacuum increase) throughline 126. Vacuum pressure transducer 124 is coupled to line 126measuring the negative pressure passing through canister 26, aspreviously discussed. If such a dramatic pressure drop occurs,transducer 124 will provide such data to controller 50 through line 128.Controller 50 will then know to shut the system down until the fullcanister is replaced with either an empty or only a partially fullcanister.

Another illustrative embodiment of a wound treatment apparatus is shownin FIG. 8 and is indicated by reference numeral 3. Apparatus 3 operatesin a similar manner as apparatus 2, with the exception of the use of two“intravenous-style” fluid bags 510, 512 suspended above housing 4 todispense the fluid. In this illustrated embodiment, posts 514, 516 withhooks 518, 520 extend upwardly of apparatus 3 from behind doors 32, 33.It will be appreciated that the posts 514, 516 may be extensible toelevate the bags 510, 512 to selected heights to provide selectedpressures for irrigation. A dispensing tube 18 extends from each bag510, 512 at one end and couples to each bandage. Gravity assists inmoving fluid through tubes 18 and into the bandages. A tube clip 522 iscoupled to each tube 18 and configured to pinch and close tube allowingthe caregiver to selectively prevent fluid from dispensing intobandages.

Illustrative vacuum bandage 314 of FIG. 3 is designed to provide aprotective environment around wound 300. Illustratively, such bandageslast for up to 7 days without having to be replaced. Bandage 314includes rinse and drain orifices (not shown) within the body of bandage314 that communicate with tubes 18, 20, respectively. Such orifices areillustratively 0.030-inch (0.08 cm) diameter and/or 0.040-inch (0.10 cm)diameter. Vacuum evacuating sub-system 66 cooperates with bandage 314,similar to bandage 14, to draw the fluid and exudate from the surface ofwound 300, and collect same into waste canister 26.

Examples of bandages 14 and 15 are shown in U.S. patent application Ser.No. 09/725,352, entitled VACUUM THERAPY AND CLEANSING DRESSING FORWOUNDS, filed on Nov. 29, 2000, and assigned to the same Assignee orAffiliated Assignee as the present disclosure, and the completedisclosure of which is hereby expressly incorporated by reference. It isfurther contemplated that other bandages may be used with this controlsystem, including bandages having separate irrigation and vacuum ports.Examples of such bandages are shown in U.S. patent application Ser. No.09/369,113, entitled WOUND TREATMENT APPARATUS, filed on Aug. 5, 1999,and assigned to the same Assignee or Affiliated Assignee as the presentdisclosure, and the complete disclosure of which is hereby expresslyincorporated by reference. The complete disclosure of U.S. patentapplication Ser. No. 10/144,504, entitled VACUUM THERAPY AND CLEANSINGDRESSING FOR WOUNDS and filed on May 13, 2002, is hereby expresslyincorporated by reference.

A side diagrammatic view of bandage 14 along with a portion of system 6is shown in FIG. 9. (See also FIG. 1.) Bandage 14 is of an illustrativetype for use with apparatus 2. (Note that the bandage is not drawn toscale.) As previously discussed, bandage 14 is a vacuum bandage. Bandage14 comprises a cover film 602, illustratively a flexible cover, thatseals wound 300 about its outer perimeter. It is contemplated, however,that film 602 can be made from an occlusive or semi-occlusive materialthat allows water vapor to permeate there through, but otherwiseprotects wound 300 from the outside environment. A bandage member 604 isplaced adjacent wound 300 and is configured to irrigate wound 300. Inthe illustrated embodiment, bandage member 604 comprises upper channels606 and lower channels 608, each provided on opposite sides 610, 612,respectively, of bandage member 604. Each of the upper channels 606 isgenerally congruent with one of the lower channels 608. Channels 606 and608 are in communication with each other via apertures 614. As shown inthe illustrated embodiment, side 612 of bandage member 604 faces wound300, and side 610 faces a porous packing 618. Packing 618 provided underfilm 602 to assist in providing a space 616 to facilitate the negativepressure. Packing 618 is typically a gauze material. It will beappreciated, however, that, for some wound care applications, thepacking 618 will not be used with member 604 under the film 602.

Illustratively, the caregiver may activate system 6, by means previouslydescribed, to draw exudate from wound 300 through channels 606, 608 andapertures 614 of bandage member 604, packing 618 and film 602, throughsplitter tube 620 connected to evacuating tube 20, and deposit incanister 26. The negative pressure applied to wound 300 created by pump110 can be applied for a period of time as determined by the caregiver.After a period of drawing, the caregiver may deactivate the negativepressure. The caregiver may begin irrigating wound 300 by releasingfluid from syringe 24, through tube 18, into splitter tube 620, throughfilm 602 and packing 618, and into bandage member 604. The fluid willtravel through channels 606 deposit in apertures 614 and irrigate wound300 by traveling through channels 608. Illustratively, the fluid willcontinue to irrigate wound 300 until space 616 can no longer receive anymore fluid. The fluid is held in space 616 for a period of time asdetermined by the caregiver. After that period, pump 110 is reactivatedand the fluid and exudate from wound 300 is evacuated from bandage 14and into canister 26 by the manner previously described. This process isrepeated as many times as necessary as determined by the caregiver.

In one embodiment, user interface 10 comprises a momentary switch (notshown) that selectively operates the aforementioned process. Forexample, the switch may be configured such that when the caregiverdepresses and holds the switch, the fluid will dispense from syringe 24into bandage 14. When the caregiver releases the switch the fluid willstop dispensing and pump 110 will activate and begin drawing the fluidand exudate. It is contemplated that the switch may be configured todelay between the vacuuming and dispensing for a period of time that isdefinable by the caregiver. It is also contemplated that all of theaforementioned descriptions as applied to system 6 are applicable tosystem 8.

The apparatus 2 is a portable, easy to use topical system that isintended to provide a protective/occlusive environment with features tofacilitate the administering of standard wound care. The apparatus 2provides for the care of two independently controlled wounds. Theapparatus 2 provides negative pressure to the wound bed, and thecaregiver can set the level of negative pressure. Illustratively, thenegative pressure is variable from 25-mmHg to 175-mmHg at increments of10-mmHg. The caregiver can choose between continuous, intermittent(profile), and no negative pressure modes. It will be appreciated thatthe apparatus 2 may be set up to provide various levels of vacuum atvarious times. The apparatus may be provided with the ability to pausenegative pressure therapy for set durations of time. The system may beset up to provide audible alarms to remind the caregiver to reset orstart a new cycle of vacuum therapy.

The apparatus 2 is intended to provide an occlusive wound healingenvironment. The apparatus 2 provides an active therapy unit thatdelivers drainage and cleansing for aggressive wound healing. It isintended, for example, for use on all pressure ulcers (Stage II throughStage IV), surgical draining wounds and leg ulcers.

In the illustrated embodiment, as shown in FIGS. 7 and 10, for example,canister 26 is configured to be received in cavity 9 disposed in side 38of housing 4. As shown specifically in FIG. 10, cavity 9 comprises twopull recesses 702, 704. Such recesses 702, 704 are concave-shapedportions formed adjacent to side 38 and to side walls 706 and 708.Recesses 702, 704 are provided to allow finger clearance when thecaregiver grasps grip portions 39, 40 of canister 26 to remove it from,or insert it into cavity 9. (See also FIGS. 1, 11 and 13.) Side walls706, 710 and bottom and top walls 708, 712 define cavity 9 such thatcavity 9 provides a relatively conforming receptacle for the canister26. The walls 706, 710 and 708, 712 conform to the size and shape of thepanels 714, 716, 718, 720 of canister 26. (See FIGS. 12 and 13.) Outlet412 of filter 108 mates with connector 416 to produce an air-tight sealbetween port 412 and connector 416. It is further contemplated thatother structures or configurations of outlet 412 and connector 416 canbe used to ensure system 6 is a closed system when canister 26 isproperly coupled to housing 4. It is still further contemplated that theaforementioned descriptions of canister 26 of system 6 apply equally tocanister 27 of system 8.

Each of top and bottom panel 718, 720 of canister 26 includes a boss722, 724, respectively. Each boss 722, 724 is configured to engage asensor such as sensor 116, 118, respectively, as depicted in FIG. 2.This engagement provides a signal to controller 50 indicating thatcanister 26 is seated properly into cavity 9 and the vacuum therapytreatment may begin to be administered. It is contemplated that bosses722, 724 can be mechanical sensors, optical, capacitive or other similartype sensors.

Side panels 714, 716 include buttons 726, 728 to assist the caregiver inplacing canister 26 in the proper location within cavity 9.Illustratively, buttons 726, 728 are small protrusions, each extendingfrom a side panel. Each button 726, 728 is configured to be received or“snapped” into corresponding dimples 730, 732, respectively, disposed inwalls 706, 710, respectively. In the illustrated embodiment, the buttonsextend from the widest point of side panels 714, 716 of canister 26.

Another wound treatment apparatus 802 is illustrated in FIG. 14.Apparatus 802 is similar in structure and function to apparatus 2,except as otherwise noted, so that identical reference numbers refer tosimilar components. Apparatus 802 has a pair of vacuum wound bandages14, a pair of dispensing lines 18, a pair of evacuating lines 20, and amain control unit 803 adapted for use with bandages 14 and lines 18, 20.Bandages 14, lines 18, 20, and control unit 803 cooperate to providedual vacuum therapy systems 806, 808.

Control unit 803 has a control module 810, a pair of fluid sources suchas syringes 24 coupled to dispensing lines 18 to provide fluid forirrigation of the wounds, and a pair of disposable waste collectioncanisters 826 coupled to evacuating lines 20 to collect waste materialsuch as exudate from the wounds and fluid from syringes 24, asillustrated in FIG. 14. Each dispensing line 18 and evacuating line 20is associated with one of bandages 14. Each syringe 24 and canister 826is provided for one of systems 806, 808. Control module 810 has ahousing 804. Syringes 24 are coupled to the front of housing 804 andcanisters 826 are coupled to the sides of housing 804, as discussed inmore detail below. Housing 804 has a handle 812 at the top thereof forhand-carrying control unit 803. A user interface 10 is centrally mountedto housing 804 between syringes 24 and canisters 826 to allow acaregiver to operate systems 806, 808.

Systems 806, 808 are similar to one another in structure and function.Thus, the following description of system 806 applies also to system808.

Housing 804 has a door 832 to partially cover syringe 24, as illustratedin FIG. 14. Door 832 is hinged to housing 804 by a pair ofvertically-spaced hinges 814 positioned along a laterally outer side 815of door 832 for movement of door 832 between opened and closedpositions. A rear side 816 of door 832 has a plurality ofvertically-spaced, horizontal mounts or grooves 817 (see FIGS. 14 and17) for receiving a flange 818 of syringe 24. Housing 804 also has aplurality of corresponding vertically-spaced, horizontal mounts orgrooves 820 (see FIGS. 14 and 17) for receiving flange 818. Duringinstallation of syringe 24, an end of a plunger 70 of syringe 24 isplaced on a vertically movable plunger interface 78 of a syringe drivemechanism, such as the one described above in connection with apparatus2, and flange 818 is inserted into one of grooves 820. Door 832 is thenclosed causing one of grooves 817 to receive flange 818 so that syringe24 is held in place by grooves 817, 820. Grooves 817, 820 supportsyringe 24 in a vertical orientation.

A door latch 822 is coupled to a laterally inner side 824 of door 832,as illustrated in FIGS. 14-16. Latch 822 is movable relative to door 832between a latched position (FIG. 16) blocking movement of door 832 fromits closed position to its opened position and a release position (FIGS.14-15) allowing door 832 to move between its closed position and itsopened position. Latch 822 has a fastener 828, such as an arm or lug,and an actuator 830 to pivot fastener 828 into and out of a slot 834 ofhousing 804 between the latched and release positions. Actuator 830 hasa stem 836 coupled to fastener 828 and a handle or door knob 838 coupledto stem 836 to rotate stem 836 and thus fastener 828 between the latchedand release positions when a caregiver rotates handle 838. Stem 836extends through an aperture of door 832. Handle 838 is coupled to oneend of stem 836 in front of door 832 and fastener 828 is coupled to anopposite end of stem 836 behind door 832.

Canister 826 is coupled to vacuum bandage 14 and other components ofapparatus 802, as illustrated, for example, in FIG. 27. Evacuating line20 is coupled to vacuum bandage 14 and an inlet port 850 of canister 826to introduce waste material into an interior region or chamber 866 ofcanister 826 through inlet port 850. A pressure sensor 124 is coupled toan upper pressure port 852 of canister 826 via a fluid line 854 (seeFIGS. 19 and 27) to sense the pressure in region 866. Pressure sensor124 sends a signal indicative of the sensed pressure to a controller850, which is common to both systems 806, 808, via an electrical line856 (see FIG. 27). A proportional valve 130 (see FIGS. 19 and 27) iscoupled to a lower outlet port 857 of canister 826 via a fluid line 858(see FIGS. 19 and 27). A pressure regulator 134 (see FIGS. 19 and 27) iscoupled to proportional valve 130 and a vacuum source 110 (see FIGS. 19and 27) via fluid lines 860 and 862, respectively (see FIG. 27). Vacuumsource 110 provides a negative or vacuum pressure within bandage 14through lines 862, 860, 858, 20 and regulator 134, valve 130, andcanister 826 to suction waste material into canister 826.

Vacuum source 110 continues to operate even if, for example, blockageoccurs somewhere upstream from vacuum source 110. If the blockagebecomes too great, vacuum source 110 could experience too great a load,or vacuum pressure. Pressure regulator 134 is provided to establish amaximum load that vacuum source 110 can experience. Pressure regulator134 allows air to be suctioned into line 862 when this maximum load isreached to protect vacuum source 110.

A filter 864 is positioned in interior region 866, as shown in FIGS. 20,23, and 27. Filter 864 covers pressure port 852 and outlet port 857 toprevent waste material from entering lines 856, 858 and possiblydamaging pressure sensor 124, proportional valve 130, pressure regulator134, or vacuum source 110. Filter 864 is, for example, a 1.0 micronteflon hydrophobic filter.

Controller 850, pressure sensor 124, and proportional valve 130cooperate to provide feedback control of the vacuum pressure provided tobandage 14. Controller 850 operates proportional valve 130 viaelectrical line 864 in response to the pressure sensed by pressuresensor 124 to provide a desired negative pressure in interior region866. A caregiver provides the desired negative pressure to controller850 through user interface 10. If, for example, pressure sensor 124senses a pressure in canister 826 that is more negative than the desirednegative pressure (which includes a suitable tolerance range),controller 850 will cause valve 130 to move closer toward its fullyclosed position so that interior region 866 experiences less of thesuction from vacuum source 110 and the pressure in canister 826 rises toapproach the desired negative pressure. On the other hand, if pressuresensor 124 sense a pressure in canister 826 that is more positive thanthe desired negative pressure, controller 850 will cause valve 130 tomove closer to its fully opened position so that interior region 866experiences more of the suction from vacuum source 110 and the pressurein canister 826 lowers to approach the desired negative pressure.

Based on readings from pressure sensor 124, controller 850 is able todetect when the waste material in canister 826 has reached a fill limit,which occurs when the waste material at least partially occludes outletport 857. As outlet port 857 becomes occluded due to the wetting offilter 864, the negative pressure established by vacuum source 110becomes blocked from interior region 866. The pressure sensed by sensor124 then begins to rise (i.e., become less negative) above the desirednegative pressure, especially if bandage 14 has a vent in communicationwith atmosphere, and air enters interior region 866 through bandage 14,line 20, and inlet port 850. In some embodiments, air enters interiorregion 866 through a bleed port (not shown) formed in housing 884 at anelevation higher than outlet port 857 instead of through the bandagevent or in addition to the bandage vent. In response to the pressurerise, controller 850 moves proportional valve 130 toward its fullyopened position to try to lower the sensed pressure to the desirednegative pressure. If vacuum source 110 is able to lower the sensedpressure to the desired negative pressure, the waste material fill limithas not been reached. If the sensed pressure remains above the desirednegative pressure, controller 850 opens proportional valve 130 furtherand compares the sensed pressure to the desired negative pressure.

Controller 850 determines that the waste material in canister 826 hasreached its fill limit when proportional valve 130 has been fully openedbut the sensed pressure remains above the desired negative pressure.This occurs because the waste material has occluded outlet port 857enough to prevent vacuum source 110 from being able to lower the sensedpressure to the desired negative pressure. Pressure sensor 124, however,is still able to sense the pressure within interior region 866 throughpressure port 852 because pressure port 852 is positioned at anelevation higher than outlet port 857. Controller 850 then activates analarm 868 via an electrical line 870 to alert a caregiver that canister826 is full and needs to be changed.

Housing 804 contains components of control unit 803, as illustrated inFIG. 19. Housing 804 has two receptacles 840, one receptacle 840 on eachside of housing 804; and each receptacle 840 is configured to receive arespective canister 826 therein. Housing 804 also has a removablevertical rear wall 842 (see FIG. 18). Behind rear wall 842 is a chamber871 (see FIG. 19). Each receptacle 840 extends toward a center ofchamber 871 from a side wall of housing 804. A printed circuit board(PCB) 872 is mounted to a rear surface of a front wall 873 of housing804 within chamber 871. Pressure sensors 124 and controller 850 aremounted to PCB 872 within chamber 871. Valves 130, pressure regulators134, vacuum sources 110, and lines 854, 858 are also positioned withinchamber 871.

A pair of mufflers 874 and a pair of muffler lines 876 are positionedwithin chamber 871. Each muffler line 876 is coupled to one of mufflers874 and one of vacuum sources 110. Illustratively, each muffler 874 hasthree disk filters 878 in series to provide three chambers 880 havingglass fiber material 882 therein to absorb sound energy. Adjacentfilters 878 are coupled together by luer-lock mechanisms.

A battery 954 rests on a bottom wall 956 of housing 804 in chamber 871,as illustrated in FIG. 19. A main power connection 958 is coupled tobattery 954 and to PCB 872. Battery 954 is illustratively a rechargeablenickel metal hydride battery that automatically recharges when mainpower connection 958 is coupled to an external electrical outlet (notshown) via a power cord (not shown), for example, and automaticallyprovides electrical power to the electrical components of control unit803 when battery 954 is charged and the power cord is disconnected fromthe external electrical outlet.

A mounting bracket 844 is coupled to an outwardly facing surface of rearwall 842, as illustrated in FIG. 18, to mount control unit 803 to asuitable control unit support (not shown). Bracket 844 has an envelope846 to receive the support through a lower opening 848. A horizontalupper wall 849 is coupled to the top of envelope 846. Envelope 846 hasinternal tapered walls 960 extending from the bottom of envelope 846 toupper wall 849. The control unit support wedges against tapered walls960 when it is inserted within envelope 846.

Canister 826 has a housing 884 providing interior region 866 to collectwaste material therein and a latch 886 to couple housing 884 to housing804 of control module 810, as illustrated in FIGS. 14 and 20-23.Canister 826 further has a cylindrical sleeve 888 carried by housing 884and extending horizontally through interior region 866. Ends of sleeve888 are appended to respective outer and inner vertical walls 891, 899of housing 884. Walls 891, 899 are each formed with an aperture 889 thatcommunicates with an interior region of sleeve 888. Latch 886 extendsthrough apertures 889 and sleeve 888 and engages a vertical back wall890 of receptacle 840, as described in more detail below.

Outer vertical wall 891 of housing 884 and sleeve 888 cooperate toprovide a monolithic unit that is coupled, such as by RF or ultrasonicwelding or adhesive, to a main portion 892 of housing 884 (see FIGS.20-23). An outer end portion 893 of sleeve 888 is formed monolithicallywith a recessed portion 894 of wall 891. Wall 891 has a peripheralflange 895 that is coupled to a corresponding peripheral flange 896 ofmain portion 892. An inner end portion 897 of sleeve 888 is coupled to arecessed portion 898 of inner vertical wall 899 of main portion 892.Outer wall 891 has inlet port 850 formed integrally therewith orappended thereto. Inner wall 899 has upper pressure port 852 and loweroutlet port 857 formed integrally therewith or appended thereto.

Latch 886 has a fastener 910 to couple to back wall 890 and an actuator912 to rotate fastener 910, as illustrated in FIGS. 21-23. Fastener 910has a pair of bayonet-style canted lugs 914 coupled to an inner endportion 916 of a shaft 918 of actuator 912. Lugs 914 are diametricallyopposed to one another and extend somewhat circumferentially and axiallyon shaft 918.

Actuator 912 further has a handle 920 coupled to an outer end portion922 of shaft 918, as illustrated in FIGS. 14, 20, 22 and 23. Handle hasa disk 924 coupled to end portion 922 and a flange 926 coupled to andextending radially outwardly from disk 924. Disk 924 and a portion offlange 926 are positioned within recessed portion 894. Recessed portion894 has a pair of stop edges 952 (see FIG. 20) positioned to restrictrotation of flange 926 to about 90 degrees.

A retainer 928 (see FIGS. 21-23) is mounted to shaft 918 between handle920 and fastener 910. Illustrative retainer 928 has a clip 930, such asan e-clip, and a clip mount 932. Clip mount 932 takes the form of a diskmounted to shaft 918 and has a circumferential groove 934 configured toreceive clip 930. Disk 932 has a diameter smaller than the innerdiameter of sleeve 888 to facilitate insertion of fastener 910 throughsleeve 888 during assembly of canister 826. After insertion of fastener910 through sleeve 888, clip 930 is positioned in groove 934 to engagerecessed portion 898 to prevent latch 886 from inadvertently withdrawingfrom sleeve 888. An inner portion of disk 932 is received in one ofapertures 889 and disk 924 is received in a space defined by an arcuateedge 950 (see FIGS. 20, 22, and 23) of wall 891 to support latch 886 forrotation relative to housing 884.

After latch 886 is coupled to housing 884, canister 826 is ready to beinstalled within receptacle 840. A caregiver places canister 826 withinreceptacle 840 (see FIG. 22) and inserts leading edges of lugs 914through an aperture 938 of back wall 890 shaped to receive lugs 914 (seeFIG. 24). The caregiver then rotates handle 920, and thus lugs 914, byhand, for example, approximately 90 degrees in a direction 936 (see FIG.25). This rotation causes lugs 914 to cam against inwardly facing thrustsurfaces 940 of back wall 890 (see FIG. 26) so that canister 826 movestoward back wall 890 and pressure port 852 and outlet port 857 are drawninto corresponding upper 904 and lower 906 sockets, respectively, ofback wall 890 (see FIGS. 22-23). Each port 852, 857 has a nipple 900that is inserted into the respective socket 904, 906 and an O-ring 902surrounding nipple 900. When lugs 914 are rotated against surfaces 940,nipples 900 are drawn into sockets 904, 906 so that O-rings 902sealingly engage tapered walls 908 of sockets 904, 906. Sockets 904, 906provide portions of lines 854, 858, respectively. A dome cover 942 ispositioned on an inner surface of back wall 890 and over lugs 914 andinner end portion 916 of shaft 918.

Canister 826 is removed from receptacle 840 and disposed of whencanister 826 is fall of waste material. To do so, a caregiver removesline 20 from inlet port 850, places a cap (not shown) on port 850 toprevent spillage, and rotates handle 920 in a reverse direction 944 torelease lugs 914 from back wall 890. The caregiver then pulls on sidegrips 946 (see FIG. 14) of canister 826 to remove canister 826 fromreceptacle 840. As canister 826 is removed from receptacle 840, lugs 914pass back through aperture 938 and pressure port 852 and outlet port 857are withdrawn from upper and lower sockets 904, 906. Canister 826 canthen be discarded and a new, empty canister 826 can be installed withinreceptacle 840.

By having latch 886 included as part of canister 826, which is disposedof after being filled with waste material, latch 886 is not used overand over again, thereby preventing lugs 914 from wearing down anddegrading the sealed connection between ports 852, 857 and sockets 904,906.

Although the foregoing apparatus has been described, one skilled in theart can easily ascertain the essential characteristics of the apparatus,and various changes and modifications may be made to adapt the varioususes and characteristics without departing from the spirit and scope ofthis disclosure, as described by the claims which follow.

1. A canister adapted for use with a vacuum wound bandage associatedwith a wound of a patient and a control module to provide a negativepressure through the vacuum wound bandage to treat the wound, thecanister comprising a housing having an interior region to collect wastematerial from the vacuum wound bandage, a latch coupled to the housingand operable to couple the housing to the control module, the latchextending through the interior region of the housing, and a sleevecarried by the housing and positioned within the interior region,wherein a portion of the latch is positioned within the sleeve, whereinthe housing has a first vertical wall and a second vertical wall, andthe sleeve extends from the first vertical wall to the second verticalwall, and wherein the first vertical wall has a first recessed portion,the second vertical wall has a second recessed portion, and the sleevehas a first end portion coupled to the first recessed portion and asecond end portion coupled to the second recessed portion.
 2. A canisteradapted for use with a vacuum wound bandage associated with a wound of apatient and a control module to provide a negative pressure through thevacuum wound bandage to treat the wound, the canister comprising ahousing having an interior region to collect waste material from thevacuum wound bandage, a latch coupled to the housing and operable tocouple the housing to the control module, the latch extending throughthe interior region of the housing, and a sleeve carried by the housingand positioned within the interior region, wherein a portion of thelatch is positioned within the sleeve, wherein the housing has a firstvertical wall and a second vertical wall, and the sleeve extends fromthe first vertical wall to the second vertical wall, wherein the firstvertical wall has a first recessed portion, the second vertical wall hasa second recessed portion, and the sleeve has a first end portioncoupled to the first recessed portion, and wherein the latch has ahandle positioned for rotation within the first recessed portion and aretainer to engage the second recessed portion to maintain the latchwithin the sleeve.
 3. A canister adapted for use with a vacuum woundbandage associated with a wound of a patient and a control module toprovide a negative pressure through the vacuum wound bandage to treatthe wound, the canister comprising a housing having an interior regionto collect waste material from the vacuum wound bandage, a latch tocouple the housing to the control module, the latch extending throughthe interior region, and a sleeve carried by the housing and positionedwithin the interior region, wherein a portion of the latch is positionedwithin the sleeve, and wherein the housing has a first vertical wall anda second vertical wall, the first vertical wall has a first recessedportion, the second vertical wall has a second recessed portion, and thesleeve has a first end portion coupled to the first recessed portion anda second end portion coupled to the second recessed portion, the latchhas a handle positioned for rotation within the first recessed portionand the first recessed portion is configured to limit rotation of thehandle to about 90 degrees.
 4. A canister adapted for use with a vacuumwound bandage associated with a wound of a patient and a control moduleto provide a negative pressure through the vacuum wound bandage to treatthe wound, the canister comprising a housing having an interior regionto collect waste material from the vacuum wound bandage, a latch tocouple the housing to the control module, the latch extending throughthe interior region, and a sleeve carried by the housing and positionedwithin the interior region, wherein a portion of the latch is positionedwithin the sleeve, and wherein the housing has a first vertical wall anda second vertical wall, the sleeve extends from the first vertical wallto the second vertical wall, the first vertical wall has an inlet portto introduce waste material from the vacuum wound bandage into theinterior region, the second vertical wall has an outlet port tocommunicate with a vacuum source of the control module, and the sleeveis lower than the inlet port and the outlet port.
 5. A canister adaptedfor use with a vacuum wound bandage associated with a wound of a patientand a control module to provide a negative pressure through the vacuumwound bandage to treat the wound, the canister comprising a housinghaving an interior region to collect waste material from the vacuumwound bandage, and a latch to couple the housing to the control module,the latch extending through the interior region, wherein the latch hasan actuator and a fastener to couple the housing to the control modulein response to rotation of the actuator, and wherein the fastener has apair of canted lugs to cam against the control module in response torotation of the actuator.
 6. A canister adapted for use with a vacuumwound bandage associated with a wound of a patient and a control moduleto provide a negative pressure through the vacuum wound bandage to treatthe wound, the canister comprising a housing having an interior regionto collect waste material from the vacuum wound bandage, and a latch tocouple the housing to the control module, the latch extending throughthe interior region, wherein the latch has an actuator and a fastener tocouple the housing to the control module in response to rotation of theactuator, wherein the actuator has a shaft coupled to the fastener andpositioned within the interior region, wherein the latch has a retainercoupled to the shaft to maintain the shaft within the interior region,and wherein the retainer has a clip and a disk having a groove, and theclip is positioned within the groove to engage the housing.